how to make language learning site?

Can anyone help me about how could i make a English language learning site.

please help me i am working on Graduation project of computer science and the idea is make a website like rosetta stone "even simpler" to learn English language,

so please tell me which programming languages should i learn and how to get started?

Some points: 1. something like rosetta stone. 2. which programming languages i need to learn? 3. all the requirements that i will need to make it.